Modder puts Super Mario 64 on PS2, hacks in co-op, and adds online multiplayer with the N64 version, all through the power of Sony's secret PS1 chip: "It works much better than I thought it was going to"

Adding local co-op to Super Mario 64 would be an impressive feat. Taking the multiplayer online would be equally astounding. Getting the classic platformer running on a PS2 would be another marvel. Doing all three at once? Now that's the stuff of modding legend, and it's exactly what YouTube Carl Does Tech Things has managed to pull off.

Getting the classic platformer running on PS2 in the first place was the easy part, it turns out, since that port is one of the many that exist in the wake of Super Mario 64's decompilation. But once Carl starts breaking down his efforts to add multiplayer in the video below (thanks, Retro Dodo), it gets pretty mind-blowing.

To enable backwards compatibility with PS1 games back in the day, Sony essentially included a full PS1 console inside of every PS2. So rather than using an actual PS2 network adapter, Carl instead connects a Pico 2 – a small Raspberry Pi device – to the console via USB. He then uses the PS1 CPU to handle network instructions back and forth between the game running on the PS2 and the Pico connecting it to the network.

PS2 + N64 Online Super Mario 64 Co-op (Real Hardware) - YouTube

Watch On

It's similar on the N64 end, where Carl uses a customized N64 cart he previously built with another Pico built-in. From there, he 'simply' adds a second instance of Mario to each game, and transmits the extra Mario's position data from one version of the game to the other.

Obviously, it's not actually that simple at all, and Carl offers an entertaining breakdown of his troubleshooting process for each issue as it comes along. My favorite detail? The difference in frame rates between the N64 and PS2 initially desynced the animations between the two consoles. That's the march of technology for ya.

But ultimately, this hacked-together project works. In fact, Carl says, "it works much better than I thought it was going to." By the end, he's got a co-op mod for Mario 64 with proper crossplay between two consoles that predate the mainstream rise of online gaming. Is there any better ode to the dedication of modders than creating something so unnecessary and yet so beautiful?

The best N64 games are always worth revisiting.